1. Field of the Invention
This invention relates to lens surface protecting procedures with particular reference to protection by taping and removal of excess tape for subsequent lens processing.
2. Description of the Prior Art
Optically finished surfaces of ophthalmic lens blanks requiring second side finishing are traditionally protected from scratching and other damage with variously applied coatings including a transparent or translucent adhesive tapes which help metal alloy used in blocking adhere to the lens blanks. The tape, being of a width greater than the maximum diameter of the lens, is usually drawn from a supply role over a lens to be covered and seated thereagainst by urging the tape and lens one toward the other.
The taped lens must then be cut away from the tape supply and/or excesses of tape at its edges prior to preparation for second side machining and polishing.
Heretofore, excesses of tape have been trimmed from taped lenses with various mechanical cutters which are required to first pierce the tape and then be so manipulated as to produce a sawing or rotary or similar cutting action about the lens edge.
With the presently available ease and rapidity of initial application of tape to lenses, i.e. as afforded by current tape dispensers and applicators, it can be appreciated that tape trimming operations such as the above become bottlenecking to production. They are unduly time-consuming, awkward and tedious. Special attention and skills are required for implementation and consistency of position of cut around lens edges.
Accordingly, it is an object of the present invention to facilitate the trimming of taped lenses, i.e. to provide for greater ease of implementation and accuracy of size, shape and position of cut.
Another object is to accomplish the above with unusual rapidity and without need for special skills;
Still another object is to provide tape cutting means which is readily adaptable to hand or machine operation.
Other objects and advantages of the invention will become readily apparent from the following description.